I-Super Absorbent Material evela kwi-Cellulose Ether

Inkqubo kunye nokusebenza kwemveliso ye-carboxymethyl cellulose cross-linked by N, N-methylenebisacrylamide ukulungiselela i-resin superabsorbent yafundwa, kwaye ukuxinwa kwe-alkali, ubuninzi be-agent edibeneyo, i-alkali etherification, kunye ne-solvent yaxoxwa. Umphumo wedosi ekusebenzeni kokufunxa kwamanzi kwimveliso. I-adsorption mechanism ye-resin efunxa amanzi emanzini iyachazwa. Uphononongo lubonise ukuba ixabiso lokugcinwa kwamanzi (WRV) le mveliso lifikelela kwi-114ml / g.

Amagama angundoqo:i-cellulose ether; i-methylenebisacrylamide; ukulungiselela

1,Intshayelelo

I-Superabsorbent resin yimathiriyeli yepolymer enamaqela aqinileyo e-hydrophilic kunye nenqanaba elithile lokuwela. Izinto eziqhelekileyo zokufunxa amanzi njengephepha, umqhaphu, kunye ne-hemp zinezinga eliphantsi lokufunxa amanzi kunye nomthamo ongemhle wogcino lwamanzi, ngelixa ii-resins ezifunxa kakhulu zinokufunxa amanzi ngokuphindwe kaninzi ubunzima bazo, kwaye ijeli eyenziwe emva kokufunxa amanzi ayizukuphelelwa ngamanzi. ngoxinzelelo oluncinci. Umthamo ogqwesileyo wogcino lwamanzi. Ayinyibiliki emanzini okanye kwizinyibilikisi zendalo.

Kukho inani elikhulu lamaqela e-hydroxyl, amaqela e-carboxyl kunye ne-sodium hydrate ion kwitsheyina lemolekyuli yezinto ezifunxa kakhulu ezenziwe ngeselulosi. Emva kokufunxa amanzi, amanzi ajikelezwe yinethiwekhi ye-hydrophilic macromolecular kwaye inokugcinwa phantsi koxinzelelo lwangaphandle. Xa amanzi enyakamisa i-adsorption resin, umaleko we-semi-permeable membrane yenziwa phakathi kwe-resin kunye namanzi. Ngenxa yoxinzelelo oluphezulu lwee-ion ezihambayo (Na +) kwi-resin efunxa amanzi, ngokutsho kukaDonnan's umgaqo wokulingana, lo mahluko woxinaniso lwe-ion unokubangela uxinzelelo lwe-osmotic. Ihlwempuzekile, lenza amandla abuthathaka athambileyo kunye nokudumba, amanzi adlula kulo maleko we-semi-permeable membrane kwaye adityaniswe namaqela e-hydrophilic kunye ne-ion kwi-macromolecules ye-resin ephezulu kakhulu, ukunciphisa ukuxinana kwee-ion ezihambayo, ngaloo ndlela kubonisa ukufunxa kwamanzi aphezulu kunye nokudumba. Le nkqubo ye-adsorption iyaqhubeka de kube umehluko woxinzelelo lwe-osmotic obangelwa ngumahluko kwi-concentration ye-ion ze-mobile ilingana nokuchasana nokwandiswa okuqhubekayo okubangelwa amandla okubambisana kwenethiwekhi ye-molecular ye-polymer resin. Izinto eziluncedo ze-superabsorbent resin ezilungiselelwe kwiselulosi zezi: izinga lokufunxa amanzi aphakathi, isantya sokufunxa amanzi akhawulezayo, ukunganyangeki kakuhle kwamanzi etyuwa, non-toxic, kulula ukuhlengahlengisa ixabiso le-pH, linokuthotywa ngokwendalo, kunye nexabiso eliphantsi, ngoko ke linobubanzi obubanzi. uluhlu losetyenziso. Ingasetyenziswa njenge-ejenti yokuthintela amanzi, i-conditioner yomhlaba, kunye ne-arhente yokugcina amanzi kwishishini kunye nezolimo. Ukongeza, inophuhliso oluhle kunye nethemba lokusetyenziswa kwezempilo, ukutya, i-microbiology, kunye namayeza.

2. Inxalenye yovavanyo

2.1 Umgaqo wovavanyo

Ukulungiswa kwe-cotton fiber superabsorbent resin ngokuyinhloko kukwenza ulwakhiwo oludibeneyo kunye neqondo eliphantsi lokutshintshwa kwesikhumba sefiber. Ukudibanisa ukudibanisa kwiikhompawundi eziqhele ukuba namaqela amabini okanye ngaphezulu asebenzayo. Amaqela asebenzayo akwazi ukudibanisa i-cross-link aquka i-vinyl, i-hydroxyl, i-carboxyl, i-amide, i-acid chloride, i-oxirane, i-nitrile, njl. Kolu vavanyo, i-N, i-N-methylenebisacrylamide isetyenziswa njenge-agent edibanisayo, kuquka la manyathelo alandelayo:

(1) I-Cellulose (i-Rcell) isabela ngesisombululo se-alkali ukuvelisa i-alkali cellulose, kunye ne-alkalization reaction ye-cellulose yi-reaction exothermic ngokukhawuleza. Ukunciphisa iqondo lobushushu kunceda ekubunjweni kwe-alkali fibers kwaye kunokuthintela i-hydrolysis yabo. Ukongeza i-alcohols kunokonyusa ukuphazamiseka kwe-cellulose, eluncedo kwi-alkalization kunye ne-etherification elandelayo.

RcellOH+NaOH→RcellONA+H2O

(2) I-alkali cellulose kunye ne-monochloroacetic acid zivelisa i-sodium carboxymethyl cellulose, kwaye i-etherification reaction iyinxalenye ye-nucleophilic substitution reaction:

RcellONA+ClCH2COONA→RcellOCH2COONA+NaCl

(3) N, N-methylenebisacrylamide cross-linked ukufumana i-resin super absorbent resin. Ngenxa yokuba kusekho inani elikhulu lamaqela e-hydroxyl kwitsheyini yemolekyuli ye-carboxymethyl fiber, i-ionization yeqela le-hydroxyl ye-cellulose kunye ne-ionization ye-acryloyl bond kabini kwikhonkco le-molecular ye-N, i-N-methylenebisacrylamide inokuqaliswa phantsi kwesenzo. yealkali catalysis, kwaye ke Cross-unxulumaniso phakathi cellulose amatyathanga molekyuli kwenzeka ngoMichael condensation, kwaye ngoko nangoko ingena proton exchange ngamanzi ukuba ibe amanzi-i-cellulose superabsorbent resin enganyibilikiyo.

2.2 Imathiriyeli ekrwada kunye nezixhobo

Izinto ezibonakalayo: i-cotton e-absorbent (inqunywe kwiilitha), i-sodium hydroxide, i-monochloroacetic acid, i-N, i-N-methylenebisacrylamide, i-ethanol epheleleyo, i-acetone.

Izixhobo zomculo: iflask enentamo ezintathu, ukushukuma kombane, i-reflux condenser, iflask yokufunxa isihluzo, i-Buchner funnel, i-oven yokucoca i-vacuum, ipompo ejikelezayo yokucoca amanzi.

2.3 Indlela yokulungiselela

2.3.1 Ukwenziwa kwealkaline

Yongeza i-1 g yomqhaphu ofunxayo kwibhotile enentamo ezintathu, emva koko wongeze umlinganiselo othile wesisombululo sesodium hydroxide kunye ne-ethanol epheleleyo, gcina ubushushu obungaphantsi kobushushu begumbi, kwaye ushukumise okwethutyana.

2.3.2 Etherification

Yongeza inani elithile le-chloroacetic acid kwaye ugxobhoze i-1h.

2.3.2 Ukudibanisa

Kwinqanaba lokugqibela le-etherification, i-N, i-N-methylenebisacrylamide yongezwa ngokulinganayo ukuze iqhube i-cross-link, kwaye ixutywe kwiqondo lokushisa kweeyure ze-2.

2.3.4 Emva kokulungiswa

Sebenzisa i-acetic acid emkhenkceni ukulungisa ixabiso le-pH ukuya ku-7, hlamba ityuwa nge-ethanol, hlamba amanzi nge-acetone, ihluzo ngokufunxa, kunye ne-vacuum yomile iiyure ezi-4 (malunga ne-60).°C, vacuum degree 8.8kPa) ukufumana imveliso yomqhaphu emhlophe.

2.4 Uvavanyo lohlalutyo

Izinga lokufunxa kwamanzi (WRV) lichongwa ngokuhluza, oko kukuthi, i-1g yemveliso (G) yongezwa kwi-beaker equkethe i-100ml yamanzi adibeneyo (V1), efakwe kwiiyure ezingama-24, ihluzwe ngesikrini sentsimbi ye-200-mesh. , kwaye amanzi asezantsi kwesikrini aqokelelwa (V2). Ifomula yokubala imi ngolu hlobo lulandelayo: WRV=(V1-V2)/G.

3. Iziphumo kunye nengxoxo

3.1 Ukukhethwa kweemeko zokusabela kwe-alkalization

Kwinkqubo yokuvelisa i-alkali cellulose ngesenzo se-cotton fiber kunye nesisombululo se-alkaline, iimeko zenkqubo zinempembelelo enkulu ekusebenzeni kwemveliso. Kukho izinto ezininzi kwi-alkalization reaction. Ukuze kube lula ukuqwalaselwa, indlela yoyilo lovavanyo lwe-orthogonal yamkelwa.

Ezinye iimeko: I-solvent yi-20ml ye-ethanol epheleleyo, umlinganiselo we-alkali kwi-etherifying agent (mol / md) ngu-3: 1, kunye ne-agent edibeneyo yi-0.05g.

Iziphumo zovavanyo zibonisa ukuba: ubudlelwane obuphambili kunye nesibini: C> A> B, umlinganiselo ongcono kakhulu: A3B3C3. Ukuxinwa kwe-lye yeyona nto ibalulekileyo kwi-alkalization reaction. Uxinzelelo oluphezulu lwe-lye lunceda ekubunjweni kwe-alkali cellulose. Nangona kunjalo, kufuneka kuqatshelwe ukuba iphezulu yoxinaniso lwelye, iphezulu isiqulatho setyuwa yeresin elungiselelwe i-superabsorbent. Ngoko ke, xa uhlamba ityuwa nge-ethanol, hlamba amaxesha amaninzi ukuze uqinisekise ukuba ityuwa kwimveliso isusiwe, ukwenzela ukuba ingachaphazeli amandla okufunxa amanzi emveliso.

3.2 Impembelelo yedosi ye-agent ye-crosslinking kwimveliso ye-WRV

Iimeko zovavanyo zezi: 20ml ye-ethanol epheleleyo, 2.3:1 umlinganiselo we-alkali kwi-etherification agent, i-20ml ye-lye, kunye ne-90min ye-alkalization.

Iziphumo zibonise ukuba inani le-agent edibeneyo edibeneyo ichaphazele i-degree-linking degree ye-CMC-Na. Ukudibanisa okugqithisileyo kukhokelela kwisakhiwo sothungelwano esiluqilima kwindawo yemveliso, ebonakaliswa ngumlinganiselo ophantsi wokufunxa amanzi kunye ne-elasticity embi emva kokungena kwamanzi; xa ubungakanani be-agent edibanisayo i-cross-link encinci, i-cross-linking ayiphelelanga, kwaye kukho iimveliso ezixutywe ngamanzi, ezichaphazela izinga lokufunxa amanzi. Xa inani le-agent edibeneyo enqamlezileyo lingaphantsi kwe-0.06g, izinga lokunyuswa kwamanzi liyenyuka ngokunyuka kwenani le-agent edibeneyo, xa inani le-agent edibeneyo lingaphezulu kwe-0.06g, izinga lokunciphisa amanzi liyancipha. kunye nenani le-arhente edibanisayo. Ngoko ke, idosi ye-agent ye-crosslinking malunga ne-6% ye-cotton fiber mass.

3.3 Impembelelo yeemeko ze-etherification kwi-WRV yemveliso

Iimeko zovavanyo zezi: i-alkali concentration 40%; umthamo wealkali 20ml; ethanol ngokupheleleyo 20ml; idosi ye-arhente edibanisayo 0.06g; alkalization 90min.

Ukusuka kwi-chemical reaction formula, i-alkali-ether ratio (NaOH:CICH2-COOH) kufuneka ibe yi-2: 1, kodwa elona xabiso le-alkali elisetyenzisiweyo likhulu kunomlinganiselo, kuba i-alkali ethile yamahhala kufuneka iqinisekiswe kwinkqubo yokusabela. , kuba: ezithile Ugxininiso oluphezulu lwesiseko samahhala lunceda ukugqitywa kwe-alkalization reaction; i-reaction cross-linking reaction kufuneka iqhutywe phantsi kweemeko ze-alkaline; ezinye iimpendulo zecala zidla ialkali. Nangona kunjalo, ukuba inani le-alkali longezwa kakhulu, i-alkali fiber iya kuthotywa kakhulu, kwaye kwangaxeshanye, ukusebenza kakuhle kwe-etherification agent kuya kuncitshiswa. Iimvavanyo zibonisa ukuba umlinganiselo we-alkali kwi-ether umalunga ne-2.5:1.

3.4 Impembelelo yesixa se-solvent

Iimeko zovavanyo zezi: i-alkali concentration 40%; idosi yealkali 20ml; umlinganiselo wealkali-ether 2.5:1; Idosi ye-agent edibanisa i-cross-linking 0.06g, i-alkalization 90min.

I-ethanol ye-solvent ye-anhydrous idlala indima yokusabalalisa, i-homogenizing kunye nokugcina imeko ye-slurry yenkqubo, enenzuzo ukusabalalisa nokudlulisa ubushushu obukhutshwe ngexesha lokubunjwa kwe-alkali cellulose, kwaye inokunciphisa ukuphendula kwe-hydrolysis ye-alkali cellulose, ngaloo ndlela ifumana iyunifomu. cellulose . Nangona kunjalo, ukuba isixa sotywala esongeziweyo sininzi kakhulu, i-alkali kunye ne-sodium monochloroacetate iya kunyibilika kuyo, ukuxinwa kwee-reactants kuya kuncipha, izinga lokuphendula liya kuncipha, kwaye kuya kuba nefuthe elibi kwi-crosslinking elandelayo. Xa isixa se-ethanol epheleleyo yi-20ml, ixabiso le-WRV likhulu.

Isishwankathelo, ezona meko zifanelekileyo zokulungiselela i-superabsorbent resin ukusuka kwikotoni efunxayo i-alkalized kunye ne-etherified carboxymethyl cellulose cross-linked by N, N-methylenebisacrylamide zezi: i-alkali concentration 40%, i-solvent-free 20ml yamanzi kunye ne-ethanol, umlinganiselo we-alkali ukuya kwi-ether. yi-2.5: 1, kunye ne-dosage ye-agent ye-crosslinking yi-0.06g (i-6% yemali ye-cotton linters).